I was looking at purchasing a focus zx3 with a bad transmission. I was thinking it would be a cheap ecomod car but the mpg isn't the greatest and the 5th gear far from perfect. Does anyone know of a transmission or gear swap to get a lower rpm in the car?

My gear change was done with the tire circumference. there is a calculator to figure rotations per mile I will copy from other thread should help.
As for sprag and gear changes seek a trans shop that build/s racing trans for these cars.
I worked at Ford when they first came out and there was a solid following of tuner crowd working these cars.

215/17/45 tire
Originally Posted by vrmilionzx
I converted to mm (so everything is in the same form of measurement), and used 25.4 mm in one inch, so:
Old Wheel Dia = 17x25.4 = 431.8mm
Old Tire height = 215mm x .45 (aspect ratio) = 96.75mm
Old combo total Dia = 431.8+(2*96.75) = 625.3mm